Pigment mixing apparatus



Nov. 14, 1939; v D, L E v 2.179.970

rmmm' MIXING APPARATUS i Filed Dec. 28, 1936 s Sheets-Sheet 1 ATTORNEY:

Nov. 14, 1939. D. A. WALLACE PIGMENT MIXING APPARATUS Filed Dec. 28, 1936 s Sheets-Sheet 2 Ill mi f t n2 1% pi ATTORNEYS.

Nov. 14, 1939. 15; A. WALLACE 2.179.970

PIGiENT HIKING APPARATUS Filed Dec. 28, 1936 3 Sheets-Sheet 3 INVE'NTOR.

Fa /id /7. flZZ/ace.

'BY V M1944; zit 9:44am- ATTORNEYS.

Patented Nov. 14, 1939 i UNITED STATES PATENT OFFICE PIGMENT MIXING APPARATUS David A. Wallace, Detroit, Mich.

Application December 28, 1936, Serial No. 117,753

7 Claims. (Cl. 259-85) The present invention relates to materialmixbetween which the material is worked to ing apparatus and in particular provides an imthoroughly mix it, and in some instances, to furproved apparatus for thoroughly mixing prether grind the pigment. One of the members is 'viously finely ground paint pigment with a prepreferably spheroidal in shape and the other of determined quantity of a medium or vehicle in hell or dome shape, fitted over the first member. 5 the manufacture of paint or other material The cooperating surfaces of one or both of the whereby pigment powders and the like are mixed members are recessed or grooved at one or more with a liquid medium. points and the previously mentioned relatively As will be appreciated from a complete underthick paste to be acted upon is fed under pres- 10 standing thereof, the improved mixing machine sure to the surfaces through these recesses. The 10 of the present invention may be used to two mixing or grinding members are preferably thoroughly mix a wide variety of materials, as urged into engaging relation to each other under well as to reduce a wide variety of materials to an adjustable fiuid or other pressure and as the a finely ground state. In the specific form illustwo mixing members are moved relatively to each trated, however, the invention is adapted parother a very thin film of the paste is continuous- 16 ticularly to the mixing of paint pigment with a ly shaved, so to speak, fromthe recessed portions suitable medium or vehicle and by way of illusand is received between the non-recessed portration, but not of limitation, the following detions of the surfaces thereof, the thinness and scription of the invention is concerned with such uniformity of the film being, of course, promoted 20 specific application thereof. by maintaining the edges of the cooperating re- 0 For the purposes of the present description, cesses in a relatively sharp condition and by the manufacture of the paint may be regarded properly proportioning the pressure exerted. as including four steps, which are first, the refin- In further accordance with the present ining and reduction to a finely divided state of the vention, the mixing together'and thoroughcoatpaint pigment; second, the mixing of the finely ing of each pigmentgranule with the vehicle or' divided pigment with suflicient medium or vemedium is promoted by the improved movements hicle to convert it into the form of a stiff paste; which are imparted to the two mixing members third, the grinding of this paste in a suitable relative to each other. As illustrated, the memmachine to thoroughly mix the medium and the bers are rotated relative to each other at a conpigment and reduce it to a relatively soft and tinuously or cyclically varying rate, and are also in some instances, to a relatively freely flowing oscillated relative to each other. The paste is paste; and fourth, the ultimate thinning of the preferably introduced between the members adpreviously mixed material to the proper consistjacent the axial centers thereof and as the mixency. The improvements of the present inven ing progresses, is forced along the surfaces and tion are concerned particularly with the third of discharged at the marginal edge of the second 35 these steps. or dome-like member, from which point it may As will be appreciated, the vehicle or medium be collected by suitable scraping or other collectusually includes an oil such as linseed, or other ing mechanism. In addition to effecting a drying oil, which acts a binder for'the pigment thorough mixing and working of the material, and produces a resistant film. On the other the foregoing structure and combination ofmo- 40 hand, the pigment acts to reinforce and strengthtions develops true spherical surfaces on the coen this film as well as, of course, providing the Operating P r s and maintains these true surdesired color. The quality of the paint depends faces until the contacting elements are worn out. very largely upon the degree of fineness of the With the foregoing considerations in view, the pigment and upon the thoroughness with which principal objects of the present invention are to 5 the medium is caused to cover and adhere to the provide a'mixlng and grinding machine embodyentire surface of the individual pigment granules. ing a pair of co-operating grinding and mixing The third one of the above enumerated four steps members, between which material to be acted is a. very important one, accordingly, and a relaupon may be fed under pressure and which, while tively wide variety of grinding and mixing maretained in co-operative relation under suitable 50 chines have heretofore been proposed for pracpressure, are moved relatively to each other to ticing it. effect the mixing or grinding action; to provide In accordance with the improvements of the such a construction in which the engaging surpresent invention, the mixing machine comprises faces of one or both of the members are recessed generally two complementary grinding members to provide wells into which the material to be 66 acted upon may be fed and out of which the material may be shaved in a uniformly thin layer by the relative motion of the two members; to provide such a construction in which the mixing or grinding members include an inner spheroidal and an outer dome-like member, adapted to be both rotated and oscillated relative to each other; to provide such a construction embodying improved motor driven means for eflecting an oscillating movement of the outer member and a rotating movement at a uniformly or cyclically variable rate of the inner member; to provide such a construction in which one of the grinding or mixing members is adapted to be water cooled; to provide such a construction in which the oscillating movement is imparted to the outer grinding or mixing member by means of a continuously rotating shaft and a ball and socket eccentric connection responsive thereto; to provide such a construction in which the drive mechanism for the inner member includes a shaft, and an oscillatable element connected between the shaft and the member for rotating such member at a continuously varying rate; to provide such a construction in which the just stated continuously rotating shaft is of tubular form to receive fluid pressure responsive elements by which the inner mixing or grinding member may be urged into engaging relation to the outer member; to provide such a construction in which the material to be mixed or ground is fed into the outer member at a point adjacent the axial center thereof, is moved by the relative movement between the mixing and grinding members along the surfaces thereof and is discharged from the outer member adjacent the marginal edge thereof; and to provide such a construction in which in different embodiments, the inner, and outer mixing or grinding members may be provided with metallic surfaces, stone surfaces, or may be separated by a plurality of ball elements.

. With the above as well as other and more specific objects, in view, which appear in the following description and the appended claims,

preferred but illustrative embodiments of the present invention are shown in the accompanying drawings, throughout which corresponding reference characters are used to designate corresponding parts, and in which:

Figure l is a view in elevation, partly in perspective, of a preferred embodiment of the invention;

Fig. 2 is a view in horizontal section, taken along the line 22 of Fig. 1;

Fig. 3 is a view in horizontal section, taken along the line 33 of Fig. 1;

Fig. 4 is a view taken along the line 4-4 of Fig. 1, but showing only the outer of the two mixing or grinding members;

Fig. 5 is a fragmentary view illustrating a further modification of the invention, in which the surfaces of the inner and outer mixing or grinding members are shown of stone;

Fig. 6 is a fragmentary view illustrating a recesses or wells in the surface of one of the grinding or mixing members;

Fig. 9 is a view corresponding generally to -Fig. 4, but illustrating a further modified ar- The inner member is provided with an upper surface 28 of spheroidal form, preferably at least hemi-spherical. The outer member 24 is provided with an inner dome-like or'spheroidal surface 30, preferably somewhat less than semispherical in extent, the engaging surfaces being concentric so that the entire inside surface of the outer member 24 is uniformly spaced from the outer surface of the inner member 20, to thus accommodate a film of uniform thickness. The degree to which the outer member 24 falls short of being hemi-spherical is so proportioned relative to the degree of oscillation imparted thereto, as hereinafter described, that this continuous complete surface cooperationis maintained in all oscillatory Positions of the two members 20 and 24 relative to each other.

The material to be mixed or ground in the machine is fed under pressure to the mixing or grindingsurfaces of the members 20 and 24 from any suitable external source (not shown) through a conduit 32, which extends through the shank 34 of the outer member 24 and opens into a series of grooves or wells 36, which are cut into the inside surface of the outer member 24 and the edges 36a of which are preferably ground to a sharp condition. A corresponding series of grooves or wells 38 are cut or recessed into the outer surface of the inner member 20. In operation, all of the wells, or recesses, or distributing channels in both the inner and outer members may be expected to be filled with the material to be mixed or ground, and, as the inner and outer members both rotate and oscillate relative to each other, causing the grooves in one member to intersect or pass across those in the other member, a relatively thin film ofthe material is continuouslyshaved from the grooves or wells in the two members and is distributed along the ungrooved portions of the surfaces. The grooves or wells in the member 24 may take any of a wide variety of forms, such as the radial fingers 36 shown in detail in Fig. 4, from each of which a plurality of supplemental fingers 36b may extend. Alternatively, the grooves or wells may be simply radially arranged as illustrated at 40 in Fig. 8, or may be spirally arranged as indicated at 42 in Fig. 9'. Similarly, corresponding arrangements of the grooves or wells in the inner member 20 may be used, and if desired, one arrangement may be used in the outer member and a difierent arrangement may be used in the inner 'member, the particular selectionand arrangement of grooves or wells in one or both of the inner and outer members being determined primarily in accordance with the particular material to be ground or mixed in the machine.

The material to be mixed or ground which, as

' from the machine in paste at the marginal edge of the previously noted, may enter the machine in the form of a relatively thick paste, after being distributed to the cooperating grinding or mixing surfaces from the wells or grooves, is discharged the form of a relatively freely flowing outer member 24. The discharged material is permitted to flow by gravity down the vertical side portions 44, and may be collected therefrom in any of a variety of ways. As illustrated, a scraper 46 is provided which engages the portion 44 of the inner member 28 and acts to accumulate the discharged material at one point, thus facilitating its removal. The scraper 46 may be supported on the main machine frame 48 by a bracket 48. Lines 25 and Him water or other coolant are connected into the outer member to effect a circulation through a chamber 21 formed therein.

Considering now the drive mechanism for the outer mixing and driving member'24, the upper end of the member 24 is formed as a ball 58, apertured to define the previously mentioned passage 32, and disposed to be received within a socket 52. Socket 52 in turn is threaded into an eccentric member 54 which is rotatably journaled in a bearing member 56 and held in place therein between locknuts 58 and a shoulder 68 formed in the eccentric 54. The bearing member 56 is suitably secured'to a bracket 62 which is pivot ally supported as at 64 upon the main machine frame 48, and which also forms a supporting bed for the motor 26. The bracket 62 may be locked in the illustrated operating position by a locking stud 66. In order to afford access to the cooperating surfaces of the inner-and outer members 28 and 24 for purposes of inspection or for re-sharpening the edges of the wells or grooves therein, the locking stud 66 may be released, permitting the bracket 62 to be swung bodily in a counter-clockwise direction as viewed in Fig. 1. If desired, the socket 52 may be so formed that the swinging of the bracket 62 carries the member 24 with it. Preferably, and as illustrated, however, the skirt portion 68 of the socket 62 is so formed that the socket 62 may be freely lifted from the ball 58, permitting the member 24 to be separately removed from the inner member 28; To accommodate this separation, a suitable connector 18 may be interposed in the line 32 and dimensioned to pass through the flared opening I2 in the socket 52. The eccentric 54 carries a worm wheel 14, disposed in continuously meshing relation to a worm l6, suitably secured upon the shaft 18 of the motor 26.

With this arrangement, as will be appreciated,

continuous rotation of the shaft 18 efi'ects a corresponding continuous rotation of the eccentric 54, thus causing the socket 52 to travel in a circular path in the plane of rotation of the'eccentric. This continuous movement effects a corresponding oscillation of the outer grinding or mixing member over the surface of the inner member 28.

The drive mechanism for the inner member 28 includes primarily the tubular shaft 88, and the bearing and supplemental driving plates 82, 84

and 86, a ring gear 88, and cooperating pinions 88. The shaft 88 is adapted to be driven continuously by the motor 22, through a worm-wheel 92 carried by the shaft 88 and a worm 94 carried by the shaft of the motor, and is suitably rotatably journaled within the main machine 48 within one or more bearing bushings such as 86. The upper end 98 of shaft 88 projects into an axial bore I88 formed in the inner member 28, and thus determines the axis of rotation of the inner member 28, while allowing the latter to move vertically with respect to the shaft 88 a limited amount, as hereinafter described.

The supplemental driving plates 82 and 84, which are spaced apart to receive between them the non-rotative internal gear 88, are connected together for simultaneous rotation as by a plurality of studs I8I and an aligning pin I82, and are driven in continuous rotation directly by the shaft 88, the lower plate 82 being formed integrally with the later member in the illustrated embodiment. The lower plate 82 is supported on a seat I84 provided therefor in the machine frame 48, a bushing I86 being interposed between these members, and thus acts to provide a thrust bearing for the shaft 88. The internal gear 88, which is supported on the machine frame, is provided with a counter-bore I88, which acts to provide a bearing for the plate 84. Plate 84 in turn provides a rotative bearing for the plate 86, a bushing I I8 being interposed between these members. In its lowest position, the member 28 rests directly upon the plate 86, and is drivingly con-' nected thereto for rotation therewith by. a plurality of studs III and one or more aligning pins such as I I2, which permit limited vertical movement of member 28 relative to plate 86.

The driving connection between the plates 82 and 84 and the plpate 86 and member 28 is afforded by one or more eccentric pinsll4 each received in a slot II6 individual thereto formed in the plate 86 and carried on a trunnion II8 which carries a pinion 88. Each pinion 98 is in continuously meshing relation to the non-rotative ring gear 88, so that it will be appreciated that a continuous bodily rotation of pinions 88 about shafts 88 as an axis, in mesh with the internal gear 88 results in a continuous rotation of eccentrics II4 about the axis of the trunnions II8. These motions of the eccentrics II4 ,effect a rotation of plate 86 and member 28, which rotation has a continuous uniform component due to the bodily rotation of eccentrics II4 about the -relation'to each other at a predetermined and adjustable pressure, to thus govern the thickness of the film of material between them. In the illustrated arrangement, this means is of the fluid pressure type, and comprises a suitable external source of supply I28, connected through a union I22 to a conduit I24 which extends through a union I22 to a conduit I24 which extends through the shaft 88 and opens into the space I26 within the bore I88 above the upper end of the shaft 88, which space thus acts as a piston chamber. With this arrangement, pressure admitted to the chamber I26 through the conduit I24, tends to cause the member 28 to move upwardly relative to the shaft 88, which movement is permitted in view 'of the slidable connection between these'members.

Any upward movement of members 28, also separates 'this member at cyclically varying rates.

through the conduit I24, and the pressure applied to the material through conduit 32, of course determines the degree of vertical displacement of the inner member 28 and correspondingly determines the thickness of the film of material interposed between the cooperating grinding or mixing surfaces 28 and 38 of the inner and outer mixed or ground is continuously feed into the space between the surfaces 28 and 38 at a suitable externally applied pressure through the supply conduit 32. The wells or recesses 38 and 38 in the cooperating surfaces 38 and 28, respec-- tively, may be expected to be continuously filled with the material to be mixed or ground. The continuously. varying rotation of the inner member 28, accompanied by the contin'uous oscillation relative thereto of the outer member 24 causes the surfaces 28 and 38 to move relative to each other in cyclically varying directions and During this movement, the movements past each other of the relatively sharp edges of the wells or recesses 38 and 38 causes a thin film of the material to be continuously shavedfrom the wells or recesses and distributed over the non-recessed portion of the cooperating surfaces 28 and 38. The subjection of this relatively thin film of material to the just mentioned continuously cyclically varying relative movement between the surfaces 28 and 38 thoroughly works the material and is found to insure a thorough coating of each granule of the paste pigment with the medium or vehicle. Depending upon the character or condition of the material at the time it is fed into the machine, the degree of pressure between the cooperating surfaces 28 and 38, the character of the cooperating surfaces 28 and 38, as well as other factors, which will be appreciatedby those familiar with machines of the character in question, the action of the machine may consist entirely in a mixing and coating of the individual pigment granules or may consist both in grinding the granules to a finer state and in coating them.

As the grinding or mixing action progresses, and as the supply of new material is continuously fed into the machine, the material-is dis-' tributed both by the supply pressure and by centrifugal force away from the axial centers of the cooperating surfaces 28 and 38, and is gradually reduced from a relatively thick paste to a relatively freely flowing paste. The thus completely mixed or ground material is permitted to ultimately discharge from the lower marginal edge of the outer member 24 and. downwardly by gravity along the substantially vertical sides 44 of the inner member 28, where it is accumulated by thescraper 48 and is ultimately collected and removed.

In the arrangement shown in Figs. 1 through 4, it is assumed that the cooperating surfaces 28 the members 28 and 24 may be provided with liners I38 and I32 respectively, of stone or other composition. As in the previous instance, the stones I88 and I82 may be provided with recesses or wells I84 and I38 respectively, within which the material to be acted upon may be received and from which it may be shaved in a relatively uniformly thin layer as previously described.

In the further modified embodiment shown in Fig. 6, a plurality of balls I 48 are interposed between the members I42 and I44, which latter members may in all other respects, except those noted below, correspond to the previously described member 28 and 24, respectively. As shown, the work surface I48 of the member I42 is hemispherical add corresponds in all respects to the surface 28 of the member 28 previously described, except that no wells or recesses are required therein. The inner surface of the member I44, on the other hand, is undercut to define a spheroidal recess I48, having the marginal re taining wall I58. Preferably the entire spheroidal recess. I48, which preferably corresponds in extent to the previously described surface 38 of the member 24, is completely filled with the balls I48.

the members I 42 and I44 causes the balls I48 to rock in successively different and widely varying directions, which rocking movement, in addition to maintaining the balls I48 in a spherical condition, also works the material in a very effective manner. The completely mixed or ground material is discharged at the marginal edge of the outer member I44 past a gasket I54, and may be collected in the previously described manner by a scraper. In all other respects, a machine embodying the arrangement of Fig. 6 may correspond in all respects to that shown with reference to Figs. 1 through 4.

In the further modified embodiment shown in Fig. 7, the one layer ball arrangement described with reference to Fig. 6, is replaced by a multiple layer ball arrangement, four layers of balls I88 being illustrated as received within a recess I62 formed in the outer member I84. In this embodiment, also, the ball section of the mixing and grinding members is confined to a predetermined portion of the cooperating surfaces, and the remaining portions such as I88 and I68 of these surfaces are arranged as described with reference to the embodiment of Fig. 1, with the exception that the wells or recesses are not required. The mixing or grinding actions are thus effected in two steps, the first step being effected through the action of the balls W8 and the second step being efiected through the frictionally acting portions I88 and I88.

It will be appreciated that in the arrangement described with reference to Figs. 1 through 4, due to the limited throw of the eccentrics I I8, the inner member 28 normally has a resultant component of rotation in the direction of rotation of the shaft 88, the rate of the oscillating component being lower than the rate of the component imparted directly by the shaft 88. This relation a fixed one in the arrangement of Fig. l in view of the fact that the internal gear 88 is nonrotatably supported.

In the modified embodiment of Fig. 10, the

previously described non-rotative mounting for imparted to the member 20 through the eccentric H4. By providing this range of adjustment, it. will be appreciated that the oscillating component may be varied relative to the main rotative component from a very small ratio to one at .which the member 20 advances in a'series of step by step movements and also to one in which the member 20 actually oscillates instead of rotating continuously in one direction. In all other. respects except the driving connection for the ring gear 88, the embodiment of Fig. 10 preferably corresponds to that described with reference to Figs. 1 through 4.

Although specific embodiments of the invention have been described. it will be appreciated that various modifications in the form, number,

and arrangement of parts may be made thereln' within the spirit and scope thereof.

What is claimed is:

1. In a machine of the class described,-an inner member having a spheroidal portion formed at the end thereof, an outer member having a spheroidal portion adapted to be fitted over said first portion, said inner and outer members being adapted to receive a film of material to be operated upon between them, means for effecting axial rotation of said inner member at a continuously varying rate, and additional means for effecting an oscillation of said outer member about said inner member, to thereby work said material.

2. In a machine of the class described, an inher member having a spheroidal portion formed at the end thereof, an outer member having a spheroidal portion adapted to be fitted over said first portion, said inner and outer members being adapted to receive a film of material to be operated upon between them, at least one of said surfaces having a material receiving well formation therein, means for introducing material to said well formation adjacent the axial center of the associated surface, and means for oscillating one of said surfaces and for rotating the other surface at a continuously varying rate to cause said material to work out of saidwell formation and distribute over the cooperating surfaces.

3. In a machine of the class described, an inner member having a spheroidal portion formed at the end thereof, an outer member having a spheroidal portion adapted to be fitted over said first portion, said inner and outer members being adapted to receive a film of material to be operated upon between them, means for introducing material between said surfaces, and means for effecting rotation and oscillation of one of said members and for causing rotation at a continuously varying rate of the other number to cause said material to work from said well formation and distribute over said cooperating surfaces.

4. In a machine of the class described, an inner member having a spheroidal portion formed at the end thereof, an outer member having a spheroidal portion adapted to be fitted over said first portion, said inner and outer members being adapted to receive a film of material to be operated upon between them, at least one of said surfaces having a material receiving well formation therein, means for introducing material to said well formation adjacent the axial center of the associated surface, means for effecting axial rotation of said inner member at a continuously varying rate, and means for effecting oscillation of said outer member to thereby cause said material to work out of said well formation and distribute over said surfaces.

5. In a machine of the class described, an inner member having a surface of spheroidal form formed at one end thereof, an outer member having a surface of spheroidal form and adapted to fit over said first surface, said surfaces being adapted to receive between them a film of material to be worked, a continuously rotating shaft, means for translating the continuous rotation of said shaft into oscillating movement of said outer -member, asecond continuously rotating shaft,

and means interposed between said second. shaft and said inner member for causing continuously varying axial rotation of said inner member in response to the rotation of said second shaft.

6. In a machine of the class described, an inner member having a surface of spheroidal form formed at one end thereof, an outer member having a surface of spheroidal form and adapted to fit over said first surface, said surfaces being adapted to receive between them a film of material to be worked, a continuously rotating shaft, means for translating the continuous rotation of said shaft into oscillating movement of said outer member, a second continuously rotating shaft, and intermediate gearing including a non-rotative gear and an eccentric element responsive thereto for causing continuously varying rotative movement of said inner member in response to rotation of said second shaft.

7. In a machine of the class described, an inner member having a surface of spheroidal form formed at one end thereof, an outer member having a surface of spheroidal form and adapted to fit over said first surface, said surfaces being adapted to receive between them a film of material to be worked, a continuously rotating shaft, means for translating the continuous rotation of said shaft into oscillating movement of said outer member, a second continuously rotating shaft, intermediate gearing interposed between said second shaft and said inner member including a rotatable gear and an eccentric element responsive thereto for causing continuously varying rotative movement of said inner member in response to rotation, and means for rotating said gear.

DAVID A. WALLACE.

CERTIFICATE or comcmom- 7 Patent No.- 2,179,97 November 11 1959.

DAVID A. muse.-

It is hereby certified that error appears in the printed specification oi the above numbered patent requiring correctiones follows: Page 3, second column, line 15, for the word "later" read latter; line 31, for "plpate" read plate; line 59, for "shafts" read shaft; lines 60 and 61, strike out the Words "which extends through a union 122 to a conduit 121 page 5,

, second colmnn, line 1, claim 5, for "number" read'member; and that the said Letters Patent should be read with this correction thereiu that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 19th day of December, A. D. 1959.

Henry Van Ar edele (3611) Acting Commissioner of Patents 

